Why does user initiated pop-under fails?

This is for Firefox 4 and 5. I know that popunders are disabled. I need to enable "Lower or raise windows" setting in the "Advanced Javascript Settings" to make the popunders work

function pop_under() {
window.blur();
window.opener.focus();
}

I understand that it is set to off by default to prevent popunders. But why shouldn't user initiated or user clicked link make the popunder work?

Regular users will not know how to change that setting.

Is there any rationale behind this?

Firefox 4 and 5 are the only ones where there is a draconian measure against the popunder.

This text is directly from the help file:
Advanced JavaScript Settings

Raise or lower windows: Uncheck this option to make sure scripts cannot raise (bring to the front) or lower (send to the back) windows.

The actual behaviour is reversed. I need to check this feature so that the scripts can raise or lower windows.

I believe this is a serious bug that only exists in Firefox 4 and 5.

This is for Firefox 4 and 5. I know that popunders are disabled. I need to enable "Lower or raise windows" setting in the "Advanced Javascript Settings" to make the popunders work
function pop_under() {
window.blur();
window.opener.focus();
}
I understand that it is set to off by default to prevent popunders. But why shouldn't user initiated or user clicked link make the popunder work?
Regular users will not know how to change that setting.
Is there any rationale behind this?
Firefox 4 and 5 are the only ones where there is a draconian measure against the popunder.
This text is directly from the help file:
Advanced JavaScript Settings
Raise or lower windows: '''Uncheck''' this option to make sure scripts cannot raise (bring to the front) or lower (send to the back) windows.
The actual behaviour is reversed. I need to check this feature so that the scripts '''can''' raise or lower windows.
I believe this is a serious bug that only exists in Firefox 4 and 5.

Do you have a page with that code to test?
Start Firefox in <u>[[Safe Mode]]</u> to check if one of the extensions is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).
*Don't make any changes on the Safe mode start window.
*https://support.mozilla.com/kb/Safe+Mode